APP ‐ HNTs Polyurea Composites Towards Mechanical Reinforcement, Flame‐Retardancy and Shock‐Wave Mitigation

ABSTRACT Recently, there has been a lot of research and study done on the risks caused by explosions. However, current explosion protection primarily focuses on secondary injuries caused by fragments, while research on primary injuries from blast shock waves and high‐temperature injuries from explosions remains relatively insufficient. In this work, leveraging the excellent mechanical properties and shock wave mitigation performance of polyurea materials, we designed a novel nano‐intercalation‐modified polyurea. The effects of the ratios and intercalation kinds of two fillers—ammonium polyphosphate (APP) and halloysite nanotubes (HNTs)—on the thermal characteristics, mechanical characteristics, and shock wave mitigation properties of the polyurea matrix were studied in detail. The experimental results show that the incorporation of APP and HNTs into the polyurea matrix can significantly enhance its mechanical strength, fire‐retardant protection, and shock wave protection capabilities. When the intercalation content of HNTs was 2% and that of APP was 30%, the modified polyurea exhibited a 35.40% reduction in peak overpressure and a 32.70% reduction in peak acceleration compared to conventional polyurea. Compared to PU‐modified polyurea, the material's ability to protect against shock waves was significantly enhanced.